Electrical transformer



(No Model.)

A. EKSTROIVI.`

ELEUTRIGAL TRANSPORMBR.

No. 508,688. Patented Nov. 14, 1893.

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UNITED STATES PATENT CFFICE.

AXEL EKSTRCM, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE GENERAL ELECTRICCOMPANY, OF NEW YORK.

ELECTRICAL TRANSFO RM ER.

SPECIFICATION forming part of Letters Patent No. 508,688, dated November14, 1893.A

` Application filed November 16,1892. Serial No. 452,146. (No model.)

To all whom it may concern:

Be it known that I, AXEL EKSTROM, a citizen of the Unitedv States,residing at Lynn, county of Essex, State of Massachusetts, have inventeda certain new and useful Improvement in Transformers, of which thefollowing is a specification.

My present invention relates to improvements in transformers, and itsparticular aim is to insure that when a number of secondaries areconnected in multiple into a single" cil'cuit they all shall be exposedto equal or substantially equal inductive effects, else the work donewill not be distributed in proper proportion between the differentsecondary coils, those doing most work will become unduly heated, andthe translating devices in the main circuit will be more or lesscornpletely short circuited through the coils doing less than theirproper fraction of work.

In the accompanying drawings Figures 1 and 2 are diagrams showing theprinciple of my invention, and Fig. 3 is a diagram of a preferredconstruction of transformer embodying my invention.

In Fig. 1 A represents a primary coil wound on a magnetic ring or coreB, and C, C' are secondary coils both connected in multiple into theline circuit D, D'. From the position given the secondaries in thisfigure, it willbe seen that coil C is nearer the primary and is exposedto considerably greater inductive action, than is the coil C' Hence itwill do more than its fair share of work, and such a transformer willnot operate satisfactorily for the reasons already outlined. If,however, the secondaries be arranged at equal distance from the primaryas is indicated in diagram in Fig. 2, then each will work properly andgood results will be secured. I have embodied this idea of equalinductive action in the 'in multiple With the work circuit Q.

Various coils of a transformer having multiplezsecondaries in theconstruction shown in Fig. 3. Here G represents a magnetic frame ofordinary construction forming a closed magnetic circuit through whichthe lines of force lthread both the primary and secondary coils. Theprimaries P, P', P2, &c., are shown connected in series with the supplyline O, and the secondaries S, S' S2, &c., are couplrd T e primary andsecondary coils` are arranged alternately, as indicated, and in suchmanner that all will be exposed to equal inductive effects from theprimaries.

Transformers having multiple primary and secondary coils With thesccondaries connected in multiple into a common circuit have previouslybeen used, but I know of no con- .structions such as claimed herein inwhich 'nected in multiple with a single work circuit,

said primary and secondary coils being alternately disposed in suchmanner that all the secondaries are exposed to equal or substantiallyequal inductive effects, substantially as described.

In testimony whereof I have hereto set my hand this 9th day of November,1892.

AXEL EKSTROM.

Witnesses:

JOHN W. GIBBONEY, BENJAMIN B. HULL.

